version 60.0.3112.10 (officail build) unknown (64 bit)
Platform 9592.9.0（official build) dev-channel link test 
Firmware Google_Link.2695.1.169


REPRO STEPS:
1.Checked <Enable swipe gestures> for US keyboard
2.Switch to US keyboard
3.Put cursor into any password input-box -> input some letters
4.Swipe the Backspace key to left

ACTUAL RESULTS
Fail to delete all inputted letters 

Note:
Swiping from the edges of the keyboard works fine